Sodium borohydride → HCID 18923296, compound

HRID 1290171Notes

Reaction equation

HRID 1290171 reaction equation
[Br:1][C:2]1[N:6]2[CH:7]=[CH:8][CH:9]=[C:10]([O:11][CH2:12][C:13]3[C:18]([N+:19]([O-])=O)=[CH:17][CH:16]=[CH:15][C:14]=3[Cl:22])[C:5]2=[N:4][C:3]=1[CH3:23].[BH4-].[Na+]>O.O.O.O.O.O.[Ni](Cl)Cl.CO>[NH2:19][C:18]1[CH:17]=[CH:16][CH:15]=[C:14]([Cl:22])[C:13]=1[CH2:12][O:11][C:10]1[C:5]2[N:6]([C:2]([Br:1])=[C:3]([CH3:23])[N:4]=2)[CH:7]=[CH:8][CH:9]=1

Participants

5

Reactant 2

HCID 4311764Sodium borohydrideHCID 9822122HCID 9822122, compound

Product 1

HCID 18923296HCID 18923296, compoundYield 14.4%

Reagents, catalysts & solvents 2

HCID 11791229Dichloronickel;hexahydrateCatalystHCID 887MethanolSolvent

Procedure

To a mixture of 3-bromo-8-(2-chloro-6-nitrobenzyloxy)-2-methylimidazo[1,2-a]pyridine (300 mg), nickel(II) chloride hexahydrate (360 mg) and methanol (9 ml) was added sodium borohydride (114 mg) portionwise under an ice-water bath cooling for 20 minutes. After stirring for 30 minutes, the mixture was concentrated in vacuo and diluted with water. The pH value of the mixture was adjusted to 3 and the separated crystals were collected by filtration. The crystals were dissolved in dichloromethane, and the solution was washed with saturated aqueous solution of sodium hydrogencarbonate, dried over magnesium sulfate and evaporated in vacuo. The residue was purified by silica gel column chromatography (3% solution of methanol in dichloromethane) and preparative thin-layer chromatography (3% solution of methanol in dichloromethane) followed by crystallization from diethyl ether to give 8-(2-amino-6-chlorobenzyloxy)-3-bromo-2-methylimidazo[1,2-a]pyridine (40 mg).

Workup

  1. temperaturecooling for 20 minutes
  2. concentrationthe mixture was concentrated in vacuo
  3. additiondiluted with water
  4. filtrationthe separated crystals were collected by filtration
  5. dissolutionThe crystals were dissolved in dichloromethane
  6. washthe solution was washed with saturated aqueous solution of sodium hydrogencarbonate
  7. dry with materialdried over magnesium sulfate
  8. customevaporated in vacuo
  9. customThe residue was purified by silica gel column chromatography (3% solution of methanol in dichloromethane)
  10. customfollowed by crystallization from diethyl ether

Sources & evidence

ORD record
ord-d795c562eab04bc28a114156b3da257f
Source dataset
uspto-grants-1998_05
Patent number
US05750699

Reaction notes

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